EP4720991A1 - Rod analysis method - Google Patents

Abstract

A method of analysing rods of aerosol-generating material within an apparatus for handling rods of aerosol-generating material is described comprising: capturing an image of an end face of a rod of aerosol-generating material as it is handled within the apparatus, wherein the captured image has a perimeter; determining rod data based on the captured image of the end face of the rod; determining one or more rod metrics from the rod data; and initiating or performing one or more actions depending on the one or more rod metrics.

Description

Rod Analysis Method

Technical Field

The present invention relates to a rod analysis system. The rod analysis system may form part of an apparatus for handling rods of aerosol-generating material, and components of such apparatus. The invention also relates to methods of handling rods of aerosol-generating material.

Background Certain tobacco industry products produce an aerosol during use, which is inhaled by a user. Such tobacco industry products commonly comprise an aerosol-generating material in the form of a cylindrical rod circumscribed by an outer wrapper.

Apparatuses are known for producing, manipulating, conveying and otherwise handling rods of aerosol-generating material during manufacture of consumables for use in aerosol-generating systems. The aerosol-generating material may include tobacco, tobacco derivatives or other types of aerosol-generating material. Such apparatuses may comprise at least one rotatable drum with elongate flutes provided around a circumferential surface of the drum to receive the rods. Such drums may be provided with suction holes communicating with the flutes to retain the rods within the flutes as the drum rotates.

Various different compositions and types of aerosol-generating material may be provided in rods intended to be conveyed through such apparatuses. Accordingly, such rods can have varying hardness, resilience and deformability. This can result in some types of rods presenting problems when being handled by known apparatuses. For example, some rods may be more easily damaged by physical contact with rod guides in known rod-handling apparatuses. Summary

The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention. According to a first aspect, there is described a method of analysing rods of aerosolgenerating material within an apparatus for handling rods of aerosol-generating material, the method comprising: capturing (e.g. using a camera) an image of an end face of a rod of aerosol-generating material as it is handled within the apparatus, wherein the captured image has a perimeter; determining rod data based on the captured image of the end face of the rod; determining one or more rod metrics from the rod data; and initiating or performing one or more actions depending on the one or more rod metrics. The one or more rod metrics may include a degree of roundness of the end face of the rod. Alternatively, or in addition, the one or more rod metrics include a circumference of the captured image.

Determining the rod data may include determining a perimeter of the rod based on positions of a plurality of points around the perimeter of captured image. Moreover, determining said one or more metrics may further comprise: determining a centre point of the captured image; and determining a distance from the determined centre point to the perimeter of the capture image at a plurality of angular positions of the rod about the centre point. Determining said one or more metrics may comprise: determining whether the determined distance at any angular position falls outside a predetermined tolerance threshold. At least one of said metrics may be based, at least in part, on a difference between maximum and minimum determined distances divided by said minimum determined distance. The method may further comprise determining a circle that approximates dimensions of the end face of the rod in the captured image. The method may comprise: determining, at plurality of different angular positions, a difference between the perimeter of the end face of the rod in the captured image and the perimeter of the determined circle; and setting at least one of said metrics accordingly. The method may further comprise: comparing a circumference of the end face of the rod in the captured image with a circumference of the determined circle; and setting at least one of said metrics accordingly.

The one or more actions may include storing some or all of the rod data and/or storing some or all of the one or more rod metrics. The one or more actions may include: outputting a rejection signal in the event that at least one of said metrics is beyond a first threshold level (e.g. above or below said threshold, depending on the circumstances). The method may further comprise setting said first threshold level.

The one or more actions may include: stopping a run, or sending an alert signal, in the event that a proportion of rods having at least one metric beyond a second threshold level (e.g. above or below the second threshold level, depending on the circumstances) exceeds a global threshold. The method may further comprise setting said second threshold level and/ or said global threshold. The second threshold may be the same as, or different to, the first threshold level outlined above.

The method may further comprise storing determined rod data and/or determined metrics for respective imaged rods or for rod materials. The method may further comprise generating rod statistics for a plurality of imaged rods. The method may further comprise correlating said statistics with possible machine errors.

According to a second aspect, there is provided a rod analysis system comprising: an imaging device (e.g. a camera) for capturing an image of an end face of a rod of aerosol- generating material as it is handled within an apparatus for handling rods, wherein the captured image has a perimeter; and a control module configured to determine rod data based on the captured image of the end face of the rod, to determine one or more rod metrics from the rod data, and to initiate one or more actions depending on the one or more metrics. The control module of the rod analysis system may be configured to perform (at least) any method as described herein (including the method of the first aspect described above).

The one or more rod metrics may include a degree of roundness of the end face of the rod. Alternatively, or in addition, the one or more rod metrics include a circumference of the captured image.

The one or more actions may include storing some or all of the rod data and/or storing some or all of the one or more rod metrics. The one or more actions may include: outputting a rejection signal in the event that at least one of said metrics is beyond a first threshold level (e.g. above or below said threshold, depending on the circumstances). The one or more actions may include: stopping a run, or sending an alert signal, in the event that a proportion of rods having at least one metric beyond a second threshold level (e.g. above or below the second threshold level, depending on the circumstances) exceeds a global threshold. The second threshold may be the same as, or different to, the first threshold level outlined above.

According to a third aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to: capture an image of an end face of a rod of aerosol-generating material as it is handled within an apparatus for handling rods, wherein the captured image has a perimeter; determine rod data based on the captured image of the end face of the rod; determine one or more rod metrics from the rod data; and initiate or perform one or more actions depending on the one or more metrics. The apparatus may be caused to perform (at least) any method as described herein (including the method of the first aspect described above). According to a fourth aspect, there is provided a computer-readable medium (such as a non-transitory computer-readable medium) comprising program instructions stored thereon for performing (at least) any method as described herein (including the method of the first aspect described above). According to a fifth aspect, there is provided an apparatus comprising: at least one processor; and at least one memory including computer program code which, when executed by the at least one processor, causes the apparatus to perform (at least) any method as described herein (including the method of the first aspect described above). Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which:

Figure 1 is a schematic block diagram of a system in accordance with an example embodiment; Figure 2 is a schematic block diagram of showing details of a rod analysis system in accordance with an example embodiment;

Figure 3 is a flow chart showing an algorithm in accordance with an example embodiment; Figure 4 is a side view of a portion of a known tobacco industry product manufacturing apparatus;

Figure 5 is a perspective view of part of the apparatus shown in Figure 4;

Figure 6 is an enlarged schematic side view of a region of the apparatus of Figure 4;

Figure 7 is a perspective view of a rod guide of the apparatus of Figure 4; Figure 8 is a schematic block diagram of a system in accordance with an example embodiment;

Figure 9 is a flow chart showing an algorithm in accordance with an example embodiment;

Figure 10 is a perspective view of the portion of an apparatus in accordance with an example embodiment;

Figure 11 is a schematic block diagram of a rod rejection system in accordance with an example embodiment;

Figure 12 is a flow chart showing an algorithm in accordance with an example embodiment; Figure 13 is a schematic block diagram of a processing system in accordance with an example embodiment;

Figure 14 is an image of a rod of aerosol generating material;

Figure 15 is a flow chart showing an algorithm in accordance with an example embodiment; Figure 16 is a plot showing an example output of the algorithm of Figure 15;

Figure 17 is an image of a rod of aerosol generating material; and

Figure 18 is a plot showing an example output of the algorithm of Figure 15.

Detailed Description As used herein, the term “delivery mechanism” is intended to encompass systems that deliver a substance to a user, and includes: combustible aerosol provision systems, such as cigarettes, cigarillos and cigars; non-combustible aerosol provision systems that release compounds from an aerosolisable material without combusting the aerosolisable material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosolisable materials; and articles comprising aerosolisable material and configured to be used in one of these non-combustible aerosol provision systems.

According to the present disclosure, a “combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is combusted or burned during use in order to facilitate deliveiy of at least one substance to a user.

In some embodiments, the disclosure relates to a component for use in a combustible aerosol provision system, such as a tobacco rod.

According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

Aerosol-generating material (which is sometimes referred to herein as an aerosolisable material) is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or semi-solid (such as a gel) which may or may not contain an active substance and/or flavourants.

The aerosol-generating material may comprise one or more active substances and/or flavours, one or more aerosol-former materials, and optionally one or more other functional material.

The aerosol-former material may comprise one or more constituents capable of forming an aerosol. In some embodiments, the aerosol-former material may comprise one or more of glycerine, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, eiythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauiyl acetate, lauric acid, myristic acid, and propylene carbonate. The one or more other functional materials may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants. The material may be present on or in a support, to form a substrate. The support may, for example, be or comprise paper, card, paperboard, cardboard, reconstituted material, a plastics material, a ceramic material, a composite material, glass, a metal, or a metal alloy. In some embodiments, the support comprises a susceptor. In some embodiments, the susceptor is embedded within the material. In some alternative embodiments, the susceptor is on one or either side of the material.

An aerosol generator is an apparatus configured to cause aerosol to be generated from the aerosol-generating material. In some embodiments, the aerosol generator is a heater configured to subject the aerosol-generating material to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol. In some embodiments, the aerosol generator is configured to cause an aerosol to be generated from the aerosol-generating material without heating. For example, the aerosol generator may be configured to subject the aerosol-generating material to one or more of vibration, increased pressure, or electrostatic energy.

In the figures described herein, like reference numerals are used to illustrate equivalent features, articles or components. Figure 1 is a schematic block diagram of a system, indicated generally by the reference numeral too, in accordance with an example embodiment. The system too comprises a drum 102 and a rod analysis system 104. The system too forms part of an apparatus for handling rods of aerosol-generating material, as discussed in detail below.

The drum 102 has a rotation axis and may have plurality of rod seats provided around an outer surface of the drum, each rod seat arranged to receive a rod of aerosolgenerating material to be conveyed by the drum (as discussed further below). The rod analysis system 104 can be used to analyse the roundness of rods of aerosol generating material handled by an apparatus including the drum 102. Figure 2 is a schematic block diagram of showing details of the rod analysis system 104, in accordance with an example embodiment. The rod analysis system 104 comprises an imaging device 112 (e.g. a camera) and a controller 114. The imaging device 112 can be used to capture one or more images of an end face of rods of aerosol-generating material in a rod-handling apparatus (such as the system too). The controller 114 may be used to analyse captured image(s) of the rod end face.

As discussed further below, the controller 114 may be configured to determine one or more rod metrics based on the captured image. Rod metrics might include a degree of roundness/ circularity of the end of a rod and/ or a rod end perimeter of the rod being processed, as discussed in detail below. The said metrics may be used (either offline or on-the-fly) to determine whether the roundness of the rod is within an acceptable tolerance range. The rods that are imaged by the imaging device 112 may, for example, be located on the drum 102 (e.g. within a rod seat of the drum). However, this is not essential to all example embodiments. For example, as discussed further below, the imaging device may image rods between a hopper and the drum. Alternatively, or in addition, the imaging device may image rods at a rod-former of the relevant apparatus.

Figure 3 is a flow chart showing an algorithm, indicated generally by the reference numeral 120, in accordance with an example embodiment.

The algorithm 120 starts at operation 122 where an image of an end face of a rod of aerosol-generating material as it is handled within a rod-handling apparatus (such as the system too) is captured, for example using a high-speed camera or some similar imaging device 112.

As discussed above, the rod-handling apparatus may comprise a drum having a rotation axis and a plurality of rod seats provided around an outer surface of the drum, each rod seat arranged to receive a rod of aerosol-generating material to be conveyed by the drum. The imaging device may, for example capture images of rods on the relevant drum, between a hopper and the drum and/or at a rod-former of the rod-forming apparatus. At operation 124, the image captured in the operation 122 is processed in order, for example, to analyse the roundness of the rod. Specifically, the roundness of the end face of the rod may be determined. As discussed in detail below, the operation 124 may include the controller 114 determining a plurality of points around a perimeter of the rod face image to determine the rod end perimeter, determining a centre point of the rod end, measuring a distance to the determined rod end perimeter from the determined centre point around a plurality of angular positions of the rod end about the centre point, and determining whether the measured distance at any angular position falls outside a predetermined tolerance threshold of all of the measured distances.

At operation 126, a determination of whether or not the rod should be accepted or rejected may be made (for example, by determining whether a particular rod is substandard according to some metric(s)). For example, the operation 126 may include rejecting a rod that has a roundness below a defined threshold (or is sub-standard in some other way). Operation 126 is shown in dotted form, as it may be provided as part of a separate algorithm (e.g. the output of the algorithm 120 may be the degree of roundness determined in operation 124). The operation 126 may be implemented by the controller 114 described above, or by some other rejection controller for identifying sub-standard rods (e.g. some other controller of the system too).

Data generated in the operation 124 may be stored for later analysis in addition to, or instead of, accepting or rejecting rods. Accordingly, in some example embodiments, the operation 126 may be omitted.

Figure 4 shows a schematic side view of a portion of a known tobacco industry product manufacturing apparatus, indicated generally by the reference numeral 10, (“apparatus” hereinafter for brevity). The apparatus 10 comprises a hopper 11 configured to receive multi-length rods of aerosol-generating material Rm (generally referred to a “rods” herein). That is, the rods Rm may have a length which is a multiple of the rod length which will be present in the final assembled aerosol-generating consumables (hereinafter “consumables”) produced by the manufacturing apparatus and which are for use in aerosol-generating systems. The rods Rm therefore generally require cutting and arranging as some of the process steps in the consumable manufacturing process.

Figure 5 is a perspective view of part of the apparatus shown in Figure 4 showing the hopper drum, grading drum, and rod guide, with the hopper omitted for clarity.

In the section of apparatus 10 shown in Figure 4, the rods Rm are conveyed from the hopper 11 by a hopper drum 12 and are cut into multiple smaller rods Rc by first and second cutting wheels 13, 14 whilst being held on the hopper drum. The cut rods Rc are then transferred to a grading drum 15. The grading drum 15 receives the cut rods Rc from the hopper drum 12 in a staggered manner to enable spacing, shuffling and rearrangement of the cut rods Rc in subsequent manufacturing steps (not shown) into the finished consumables. In use, the hopper drum 12 may rotate in a clockwise direction and grading drum 15 may rotate in an anti-clockwise direction in the view shown in Figure 4.

The hopper drum 12 is disposed adjacent the hopper 11 and is configured to receive rods Rm from within the hopper 11 and to convey them away from the hopper 11 for processing into consumables in later processing steps of the apparatus 10 (not shown in detail herein).

The hopper drum 12 is shown in more detail in Figure 5 and is a cylindrical component having a central axis and a bore 18 extending axially through the drum 12. The hopper drum 12 is rotatable within the apparatus 10 by being mounted to a rotatable shaft 19 of the apparatus 10 with the rotatable shaft 19 extending through the bore 18. The hopper drum 12 has first and second end faces 20, 21 and a circumferential outer surface extending around the hopper drum 12 between the end faces 20, 21. The outer surface includes a plurality of flutes 23. The flutes 23 are curved depressions or recesses which are configured to receive the rods Rm from the hopper 11 and to retain the rods Rm within the flute 23 as the hopper drum 12 rotates to convey the rods Rm away from the hopper 11 and onwards within the apparatus 10 for processing into consumables. The flutes 23 are elongate and extend in an axial direction of the hopper drum 12. That is, the flutes 23 lie with their elongate length extending in a direction aligned in parallel with the central axis of the hopper drum 12. Figure 6 is an enlarged schematic side view of a region of the apparatus of Figure 4 showing the interaction between the hopper drum and rod guide, and also illustrating the grading drum. A plurality of circumferential grooves 24 are formed in the outer surface of the hopper drum 12. The grooves 24 extend radially inwardly such that they extend into and intersect the flutes 23. A plurality of vacuum ducts 25 (see Figure 6) extend through the body of the hopper drum 12 in a direction parallel to the central axis of the hopper drum. The vacuum ducts 25 are arranged circumferentially around the hopper drum 12 and radially inwardly of the flutes 23. Each vacuum duct 25 is open at the first end face 20 of the hopper drum 12 at a respective vacuum port 26. The vacuum ports 26 are therefore disposed in a circular arrangement on the first end face 20 of the hopper drum 12 and at a radial distance rv measured from the central axis of the hopper drum 12/rotatable shaft 19 (see Figure 6). Each flute 23 is provided with a plurality of suction holes 27 which are in fluid communication with an associated respective vacuum duct 25. In an embodiment, each vacuum duct 25 may communicate with the suction holes 27 in two adjacent rows of flutes 23, as shown in Figure 6. In other embodiments, each vacuum duct 25 may communicate with the suction holes 27 in only one row of flutes 23, or more than two rows of flutes 23. Thereby, a vacuum can be applied to suctions holes 27 of one or more flutes 23 by applying a vacuum to the vacuum port 26 of the associated vacuum duct 25.

The apparatus 10 includes a side retaining plate 28 which extends around a part of the circumference of the end faces 20, 21 of the hopper drum 12 (as shown in Figure 4). A lower transfer surface 29 is provided beneath the hopper drum 12 over its axial length, and extending around a part of the circumference of the hopper drum 12 in that bottom region of the hopper drum 12. In use, the lower transfer surface 29 assists the transfer of the cut rods Rc from the hopper drum 12 to the grading drum 15, as described in more detail below.

Guide members in the form of said rod guides 35 are disposed at the bottom region of the hopper drum 12 and comprise elongate arms disposed generally horizontally and extending substantially tangentially relative to the hopper drum 12 (see Figures 4 and 6). A possible configuration of rod guide 35 is shown in Figure 7. Each rod guide 35 comprises an elongate arm having a longitudinal axis D-D. In use, the longitudinal axis D-D would lie substantially along the horizontal. The rod guide 35 includes mounting apertures 36 for fixing the rod guide 35 to the apparatus 10 by mounting bolts 37 as shown in Figure 4. The rod guide 35 includes an inclined guide surface 38 at the opposite end of the rod guide 35 to the mounting apertures 36. The rod guides 35 are fixed in the apparatus 10 such that the guide surface 38 locates at least partially within the grooves 24 in the hopper drum 12, and within the flutes 23.

The cutting wheels 13, 14 are mounted adjacent the hopper drum 12 and are staggered in an axial direction of the hopper drum 12 and in a circumferential direction of the hopper drum 12. A perimeter cutting edge 39 of each cutting wheel 13, 14 intersects the outer surface of the hopper drum 12 and extends into a respective cutting groove 40 which is formed circumferentially around the outer surface of the hopper drum 12 and extends through each flute 23. As such, rods Rm which are received in the flutes 23 may be cut into individual smaller cut rods Rc as they pass the cutting wheels 13, 14 as the hopper drum 12 rotates.

The grading drum 15 is shown in perspective view in Figure 5 and comprises a cylindrical component having a central axis and a bore 44 extending axially through the drum 15. The grading drum 15 is rotatably mounted beneath the hopper drum 12 as shown in Figure 4. The grading drum 15 has a circumferential outer surface 45 extending around the grading drum. The outer surface 45 includes a plurality of rod seats 46 configured to receive the cut rods Rc from the hopper drum 12/lower transfer surface 29 as the hopper drum 12 rotates, to convey the cut rods Rc away from the hopper drum 12 and onwards within the apparatus 10 for processing into consumables.

The lower transfer surface 29 includes slots 47 through which the rod seats 46 of the grading drum 15 rotate as they pass close to the hopper drum 12 to enable the rod seats 46 to collect the cut rods Rc from the hopper drum 12. The rod seats 46 are circumferentially staggered when viewed in an axial direction of the grading drum 15. This allows the cut rods Rc from one axial row on the hopper drum 12 (i.e. which are axially-aligned in one flute 23 on the hopper drum 12) to be picked up by the grading drum 15 at staggered intervals so they become axially off-set once on the grading drum

15-

Operation of the known apparatus shown in Figure 4 will now be described. The hopper 11 is provided with multiple length rods Rm. The rods Rm are held in the hopper 11 arranged with their axes in parallel and in parallel with the axis of the hopper drum 12. The hopper drum 12 rotates in the clockwise direction and as a region of the hopper drum 12 passes through a transfer region of the hopper 11, each flute 23 picks up an individual rod Rm and conveys it around and out of the hopper 11. The control flange 30 remains fixed in the apparatus 10 as the hopper drum 12 rotates. As the rods Rm pass the cutting wheels 13, 14, the cutting wheels 13, 14 cut the rods Rm into smaller individual cut rods Rc as they are held within the flutes 23.

As the hopper drum 12 rotates, the vacuum ports 26 are open to atmosphere as some rotational angles. This removes the suction force through the suction holes 27 in the flutes 23 and allows the cut rods Rc to be released from the flutes 23. The cut rods Rc are conveyed around the lower region of the hopper drum 12 over the lower transfer surface 29 until the cut rods Rc are picked up by the grading drum 15 at an upper region thereof. The rod seats 46 of the grading drum 15 pass close to the bottom of the hopper drum 12 though the slots 47 in the lower transfer surface 29. Thereby, as the cut rods Rc leave the flutes 23 they are picked up by a respective rod seat 46 of the grading drum 15 and conveyed onwards in the rod seat 46 as flute 23 of the hopper drum 12 rotates away from the grading drum 15 and back towards the hopper 11 to collect another multi-length rod Rm. In ideal operation, the cut rods Rc will consistently, quickly and evenly fall from the respective flute 23 of the hopper drum 12 due to gravity when the suction force is removed from the suction holes 27. However, some rods Rm/Rc of certain compositions of aerosol-generating material being processed by the apparatus 10, may have certain material properties (such as hardness, resilience or elastic/plastic deformability) or dimensions (such as lack of “roundness”) - which can present problems in the cut rods Rc leaving the flutes 23. In some cases, the cut rods may become stuck in the flute, even when the suction force is removed. In particular, rods Rc comprising an aerosol-generating material with a softer material property may tend to deform more easily and become trapped in the flutes 23. This can lead to manufacturing faults, machineiy jamming, or at the least, wasted rod material as the rod Rc will be lost from the manufacturing line or actively removed and disposed of.

Some rods can enter the hopper drum 12 with variability in circumference and/or circularity (or roundness). Alternatively, or in addition, the roundness can be affected by processing steps. For example, the above-described use of the rod guides 35 is effective at removing cut rods Rc from the flutes 23 and/ or aiding rod movement at speed towards the grading drum 15. However, problems can arise due to the force with which the rods Rc may abut the guide surface 38 of the rod guide 35. Such impact may dent or damage the cut rods Rc, which can cause uneven or damaged consumables being produced. Furthermore, the cut rods Rc may be deflected unevenly from the flutes 23 which may cause them to be inconsistently collected by the grading drum 15.

Variability in roundness and/or circumference can affect both product quality and machine-run reliability. Rod variability can lead to many problems, including hopper jams, fill ratio variability and transportation problems.

Figure 8 is a schematic block diagram of a system, indicated generally by the reference numeral 130, in accordance with an example embodiment. The system 130 comprises a hopper 134, a hopper drum 135 and a grading drum 136 (which may be the hopper 11, the hopper drum 12 and the grading drum 15 described above). The system 130 also comprises a rod analysis system, indicated generally by the reference numeral 131. The rod analysis system 131 is an example implementation of the rod analysis system 104 described above.

The rod analysis system 131 comprises a camera 132 (to capture an image of an end face of rods of aerosol-generating material in the apparatus) and a controller 133. The camera is typically orientated such that, in use, end faces of rods pass through a field of view of the camera. The controller 133 includes a processor configured to analyse the captured image of the rod end face in order to analyse the roundness of rods of aerosol generating material handled by the apparatus.

The camera 132 is shown in three possible positions in the system 300, indicated by the reference numerals 132a, 132b and 132c respectively. Note that in some example embodiments, more than one camera may be provided (e.g. in more than one of the positions 132a, 132b and 132c). Alternatively, or in addition, one or more cameras may be provided in one or more other positions (such as at a rod-forming location).

The camera 132 may be configured to image rods between the hopper 134 and the hopper drum 135 (as indicated by the camera 132a). The camera 132a may, for example, be configured to image rods whilst the rods are being pulled from the hopper 134. Alternatively, or in addition, the camera may be configured to image rods on the hopper drum 135 (as indicated by the camera 132b). The camera 132b may therefore generate images of rods on the first drum after the hopper 134. This may enable defective rods to be removed as soon as possible (potentially reducing machine downtime).

Alternatively, or in addition, the camera may be configured to image rods on the grading drum 136 (as indicated by the camera 132c). This is the same as the position of the camera 152 described below. Figure 9 is a flow chart showing an algorithm, indicated generally by the reference numeral 140, in accordance with an example embodiment. The algorithm 140 maybe implemented by the system 130 described above.

The algorithm 140 starts at operation 142 where an imaging device (such as the camera 132 described above) is orientated such that, in use, end faces of rods passing through a system (such as the rod handling system too) pass through a field of view of the imaging device. The operation 142 may form part of an initiation or setup process and may only be performed once (and may, indeed, be omitted from some implementations of the algorithm 140).

At operation 144 (which is similar to the operation 122 described above), an image of an end face of a rod of aerosol-generating material as it is handled within a rod-handling apparatus is captured, for example using a high-speed camera (e.g. camera 132) or some similar imaging device 112.

As discussed above, the rod-handling apparatus may comprise a drum having a rotation axis and a plurality of rod seats provided around an outer surface of the drum, each rod seat arranged to receive a rod of aerosol-generating material to be conveyed by the drum. The imaging device may, for example capture images of rods on the relevant drum, between a hopper and the drum and/or at a rod-former of the rod-forming apparatus. Imaging on the drum may offer some advantages; for example, the rods arrive at a consistent location in a predictable manner, such that measurements and determination of differences between measurements, tend to be reliable. At operation 146 (which is similar to the operation 124 described above), the image captured in the operation 144 is processed in order, for example, to analyse the roundness of the rod. Specifically, the roundness of the end face of the rod may be determined. The operation 146 may include the controller 133 determining a plurality of points around a perimeter of the rod face image to determine the rod end perimeter, determining a centre point of the rod end, measuring a distance to the determined rod end perimeter from the determined centre point around a plurality of angular positions of the rod end about the centre point, and determining whether the measured distance at any angular position falls outside a predetermined tolerance threshold of all of the measured distances. At operation 148, sub-standard rods are identified. Any identified sub-standard rods may then be rejected. For example, as described above with reference to the operation 126, the operation 148 may include identifying rods having a roundness below a defined threshold (or that is sub-standard in some other way). It should be noted that the operation 148 may be performed on-the-fly (e.g. to identify sub-standard rods during processing). Alternatively, the operation 148 may be performed later, based on historical data. For example, the operation 148 may be implemented after a run has been completed, or after a fault has occurred (e.g. requiring a manufacturing apparatus, such as the apparatus 10, to be shut down). Figure 10 is a perspective view of the portion of an apparatus, indicated generally by the reference numeral 150, in accordance with an example embodiment. The apparatus 150 includes the hopper drum 12 and the grading drum 15 described above (or the hopper drum 135 and the grading drum 136), and further comprises a camera 152 and a camera frame 154. The camera 152 may be used to capture the images discussed in operation 144 of the algorithm 140. The camera 152 may, for example, be the camera 132c of the system 130. Of course, as discussed above, the camera 152 may be provided in a different position. Moreover, one or more further cameras may be provided in the apparatus 150. The camera 152 is oriented with a focal direction in parallel with the axial direction of the hopper drum 12 and the grading drum 15.

The camera 152 is typically a high speed camera, thereby enabling articles that are passing quickly through the apparatus 150 to be analysed. Commercially available cameras have been found to be suitable for this purpose. Figure n is a schematic block diagram of a rod rejection system, indicated generally by the reference numeral 160, in accordance with an example embodiment. The rod rejection system 160 comprises a rejection controller 162 and a rod rejection apparatus 164. The controller 162 identifies sub-standard rods and may be implemented as part of the controller 133 or the controller 114 described above.

The rod rejection apparatus 164 is configured to discharge sub-standard rods from the relevant apparatus in some way. The rod rejection apparatus may take many forms. These include a reduction of flute vacuum pressure/pressurised air jet at rejection location and/ or the provision of a pressurised air jet at a rejection location.

Alternatively, or in addition, a solid member having a movable position could be provided to eject rods (such as a simple arm to “pull off’ or otherwise eject rejected rods). The skilled person will be aware of other options for implementing the rod rejection apparatus 164.

Figure 12 is a flow chart showing an algorithm, indicated generally by the reference numeral 200, in accordance with an example embodiment.

The algorithm 200 starts at operation 202, where one or more images are captured of an end face of a rod of aerosol-generating material as it is handled within the apparatus.

At operation 203, rod data is determined based on the image captured in the operation 202. The rod data may include information such as which pixels of the image are occupied by the rod, where the perimeter of the rod is etc. The rod data determined in the operation 203 may be referred to as raw data.

At operation 204, one or more rod metric(s) are determined from the rod data. The said metric(s) may relate to a degree of roundness of the end face of the rod (i.e. rod circularity), as discussed further below. Other metrics that might be determined (in addition to, or instead of, the degree of roundness) include a rod end perimeter based on the captured image and/or an indication of the rod end circumference.

At operation 206, some or all of the rod data determined in the operation 203 and/or some or all of the rod metrics determined in the operation 204 are stored. Data for individual rods may be stored (e.g. including rod data measurements). Alternatively, or in addition, rod data or metrics relating to a plurality of rods may be stored (e.g. rod statistics for a plurality of imaged rods). Alternatively, or in addition, data relating to rod materials being input into the apparatus (rather than for specific rods) may be generated and stored.

At least some data or metrics may be stored in the operation 206 for future analysis. As noted above, such future analysis may be performed after a fault has been detected.

At operation 208, a determination may be made (based on the metric(s) determined in the operation 204) regarding whether or not a rod should be accepted to rejected. For example, a rejection signal may be generated in the event that a determined metric is below a threshold level.

The operation 208 may be triggered in response to a decision to reject a particular rod. Alternatively, or in addition, the operation 208 may, include action being taken (such as stopping a run or sending an alert signal) in the event that a proportion of rods having a metric below a threshold level exceeds a global threshold.

Note that one or both of the operations 206 and 208 may be omitted in some example embodiments. For example, the algorithm 200 may be used to collect data for future analysis (in which case the operation 208 maybe optional). Alternatively, the algorithm may be used for accepting or rejecting rods on-the-fly (in which case the operation 206 may be optional). Moreover, some other action may be taken in response to the determined metrics (in addition to, or instead of, the operations 206 and/or 208).

Figure 13 is a schematic block diagram of a processing system, indicated generally by the reference numeral 210, in accordance with an example embodiment. The processing system 210 comprises a processor 212 and a memoiy 214 (such as RAM and/or ROM) coupled to the processor. The memory 214 may store computer program code, which, when executed by the processor 212, causes the processing system 210 to implement one or more of the algorithms described herein (such as the algorithm 120 or the algorithm 200).

The processor 212 may be used to process images captured in the operation 202. Thus, for example, the processor 212 may implement one or more of the operations 203, 204, 206 and 208 of the algorithm 200. The processor 212 may provide an output, for example data and/or metrics for storage (implementing the operation 206) and/or an output indicating whether a rod of aerosol-generating material should be rejected (implementing the operation 208). Figure 14 is an image of a rod 300 of aerosol generating material. It is readily apparent that the rod 300 has a high degree of circularity.

Figure 15 is a flow chart showing an algorithm, indicated generally by the reference numeral 310, in accordance with an example embodiment. The algorithm 310 may be used to determine information regarding the rod 300.

The algorithm 310 starts at operation 312, where an image of the rod 300 is captured. The operation 310 is an example of the operation 202 of the algorithm 200 described above.

At operation 314, a circle that best fits the image of the rod is generated.

Circle data is determined at operation 316. The circle data may, for example, include a radius and/or a circumference of the circle generated in the operation 314.

Finally, rod data is determined in operation 318 based, in part, on the circle data generated in the operation 316.

Of course, although the operations 314 to 318 are shown as separate steps, some or all of those steps may be merged.

Figure 16 is a plot, indicated generally by the reference numeral 320, showing an output of the algorithm 310. The plot 320 shows an image of the rod 300, as generated in the operation 312 of the algorithm 310.

The plot 320 has a circle 322 drawn around the image 320, as generated in the operation 314. Information such as a centre point, radius and circumference of the circle can readily be determined. The circle 322 may be generated in many ways. For example, a rod end perimeter may be determined and a plurality of points around the perimeter of the rod face image determined and/or a centre point of the rod end face image may be determined. These points may be used to determine a best fit for the circle and a centre point of the circle.

Data relating to the circle and to the rod is displayed in the image 320. The rod is number 53 of the rods processed. The circle 322 has a circumference (as determined in the operation 316) of 22.592mm.

The generating of the rod data (in the operation 318) may include determining a distance to the determined rod end perimeter from the determined centre point around a plurality of angular positions of the rod end about the centre point. By determining discrepancies between determined perimeters at plurality of rod angular positions and the perimeter of the perfect circle 322, an estimate of roundness or circularity can be determined. A circularity of 90.318% is determined in the example shown. The plot 320 also displays an average circumference (22.618mm) and average circularity (88.843%) for rods that have been measured. The plot indicates that the rod 300 has a slightly higher roundness than average.

As noted above, the operation 312 of the algorithm 300 is an example of the operation 202 of the algorithm 200. Moreover, the operations 314 to 318 may be used to implement the operations 203 and 204.

The operation 208 of the algorithm 200 may be implemented based on the data determined in the operations 314 to 318. For example, a determination may be made regarding whether the measured distance at any angular position falls outside a predetermined tolerance threshold of all of the measured distances. This may be indicative of a fault (which may be stored as information and/or used to reject the respective rod). Alternatively, or in addition, a metric may be determined based on a difference between maximum and minimum determined distances from the centre point to the perimeter of the rod, divided by said minimum determined distance. Again, this metric may be used to identify a likely fault.

In the event that a determined metric is outside an acceptable range (which range may be user definable, or set in some other way), a rejection signal may be generated (in an example implementation of the operation 208) . Figure 17 is an image of a rod 330 of aerosol generating material. The rod 330 is damaged. It is readily apparent that the rod 330 has a lower circularity than the rod 300 shown in FIG. 14. Figure 18 is a plot, indicated generally by the reference numeral 340, showing an output of the algorithm of Figure 15, based on an image of the rod 330 (as generated in the operation 312 of the algorithm 310).

The plot 340 has a circle 342 drawn around the image 340, as generated in the operation 314. A centre point, radius and circumference of the circle 342 can readily be determined.

Data relating to the circle 342 and to the rod 330 are displayed in the image 340. The rod is number 50 of the rods processed. The circle 342 has a circumference (as determined in the operation 316) of 22.028mm and a circularity of 76.277%. This is less than the average circularity (78.892%) indicating that the rod 330 has a degree of damage.

In the event that a determined metric (such as the circularity) is outside an acceptable range (which range may be user definable, or set in some other way), a rejection signal may be generated (in an example implementation of the operation 208).

Apparatuses are described above for handling rods of aerosol-generating material from a hopper 11 (or 134) to a grading drum 15 (or 136). Such apparatuses may form part of a larger manufacturing machine which may include further stations for handling, processing, assembling and collating rods into consumables or groups of consumables. Such machine may comprise a single machine and the apparatus 10 may comprise a section of such a machine. Such a machine may comprise a modular machine comprising separate modules assembled and connected together to perform the desired function and manufacturing steps, and the apparatus may comprise a discrete module of such a modular machine, or a portion of such a module of such a modular machine. For example, the apparatus 10 may comprise the hopper, hopper drum 12, and grading drum 15 (and associated components described above). Alternatively, the apparatus 10 may comprise only the hopper drum 12 without also the grading drum 15 or other drums upstream or downstream of the hopper drum 12 in the apparatus. As mentioned above, in such context, the apparatus may comprise a drum other than a hopper drum 12 within the scope of the invention.

In the embodiments shown, the flutes 23 are formed integrally with the hopper drum 12 on the outer surface of the drum 12. However, the flutes 23 may be provided as one or more separate components attached to a surface of a drum.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive.

It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

Claims

1. A method of analysing rods of aerosol-generating material within an apparatus for handling rods of aerosol-generating material, the method comprising: capturing an image of an end face of a rod of aerosol-generating material as it is handled within the apparatus, wherein the captured image has a perimeter; determining rod data based on the captured image of the end face of the rod; determining one or more rod metrics from the rod data; and initiating or performing one or more actions depending on the one or more rod metrics.

2. A method as claimed in claim 1, wherein the one or more rod metrics include a degree of roundness of the end face of the rod.

3. A method as claimed in claim 1 or claim 2, wherein the one or more rod metrics include a circumference of the captured image.

4. A method as claimed in any one of claims 1 to 3, wherein determining the rod data includes determining a perimeter of the rod based on positions of a plurality of points around the perimeter of captured image.

5. A method as claimed in claim 4, wherein determining said one or more metrics further comprises: determining a centre point of the captured image; and determining a distance from the determined centre point to the perimeter of the capture image at a plurality of angular positions of the rod about the centre point.

6. A method as claimed in claim 5, wherein determining said one or more metrics comprises: determining whether the determined distance at any angular position falls outside a predetermined tolerance threshold.

7. A method as claimed in claim 5 or claim 6, wherein at least one metric is based, at least in part, on a difference between maximum and minimum determined distances divided by said minimum determined distance.

8. A method as claimed in any one of claims 1 to 7, further comprising determining a circle that approximates dimensions of the end face of the rod in the captured image.

9. A method as claimed in claim 8, further comprising: determining, at plurality of different angular positions, a difference between the perimeter of the end face of the rod in the captured image and the perimeter of the determined circle; and setting at least one of said metrics accordingly.

10. A method as claimed in claim 8 or claim 9, further comprising: comparing a circumference of the end face of the rod in the captured image with a circumference of the determined circle; and setting at least one of said metrics accordingly.

11. A method as claimed in any one of claims 1 to 10, wherein the one or more actions include storing some or all of the rod data and/or storing some or all of the one or more rod metrics.

12. A method as claimed in any one of claims 1 to 11, wherein the one or more actions include: outputting a rejection signal in the event that at least one of said metrics is beyond a first threshold level.

13. A method as claimed in claim 12, further comprising: setting said first threshold level.

14. A method as claimed in any one of claims 1 to 13, wherein the one or more actions include: stopping a run, or sending an alert signal, in the event that a proportion of rods having at least one metric beyond a second threshold level exceeds a global threshold.

15. A method as claimed in claim 14, further comprising setting said second threshold level and/or said global threshold.

16. A method as claimed in any one of claims 1 to 15, further comprising: storing determined rod data and/or determined metrics for respective imaged rods or for rod materials.

17. A method as claimed in claim 16, further comprising: generating rod statistics for a plurality of imaged rods.

18. A method as claimed in claim 17, further comprising: correlating said statistics with possible machine errors.

19. A rod analysis system comprising: an imaging device for capturing an image of an end face of a rod of aerosolgenerating material as it is handled within an apparatus for handling rods, wherein the captured image has a perimeter; and a control module configured to determine rod data based on the captured image of the end face of the rod, to determine one or more rod metrics from the rod data, and to initiate one or more actions depending on the one or more metrics.

20. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to: capture an image of an end face of a rod of aerosol-generating material as it is handled within an apparatus for handling rods, wherein the captured image has a perimeter; determine rod data based on the captured image of the end face of the rod; determine one or more rod metrics from the rod data; and initiate or perform one or more actions depending on the one or more metrics.